Hi, Sandman1268!
There are no subliminals! It is good that you noticed the headache. Your body has a great feedback mechanism!
Go with how you feel rather than the number of times suggested. Stop after one time of playing the fields and then assess how you feel. This is according to personal needs and reactions, and not a “you have to do ___ many” recommendation. Tune into you and don’t overdo! Wow, that rhymes, lol. 
Also, there is an FAQ for the forum here
And make the little magnifying glass in the upper right corner of your screen a close friend! You can search for anything, especially to see if your particular question has already been answered.
Enjoy the forum!